US4305005A - Load controller - Google Patents

Load controller Download PDF

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Publication number
US4305005A
US4305005A US06/005,304 US530479A US4305005A US 4305005 A US4305005 A US 4305005A US 530479 A US530479 A US 530479A US 4305005 A US4305005 A US 4305005A
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United States
Prior art keywords
power
storage
temperature
controller
temperatures
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Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US06/005,304
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English (en)
Inventor
James L. McKenney
Robert H. Stevenson
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
DRC Inc A CORP OF RI
MEGATHERM Inc A RI CORP
Original Assignee
Vapor Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Vapor Corp filed Critical Vapor Corp
Priority to US06/005,304 priority Critical patent/US4305005A/en
Priority to GB7940472A priority patent/GB2042767A/en
Priority to CA000340423A priority patent/CA1144234A/en
Priority to FR8001232A priority patent/FR2447125A1/fr
Priority to US06/283,365 priority patent/US4362949A/en
Application granted granted Critical
Publication of US4305005A publication Critical patent/US4305005A/en
Assigned to DRC, INC. A CORP. OF RI reassignment DRC, INC. A CORP. OF RI ASSIGNMENT OF ASSIGNORS INTEREST. Assignors: VAPOR CORPORATION A DE CORP
Assigned to STIEBEL ELTRON NOTH AMERICA, INC. A DE CORP reassignment STIEBEL ELTRON NOTH AMERICA, INC. A DE CORP ASSIGNMENT OF ASSIGNORS INTEREST. Assignors: DRC, INC. A CORP. OF RI
Assigned to MEGATHERM, INC., A RI CORP reassignment MEGATHERM, INC., A RI CORP ASSIGNMENT OF ASSIGNORS INTEREST. Assignors: STIEBEL ELTRON NORTH AMERICA, INC., A DE CORP
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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    • G—PHYSICS
    • G05—CONTROLLING; REGULATING
    • G05D—SYSTEMS FOR CONTROLLING OR REGULATING NON-ELECTRIC VARIABLES
    • G05D23/00—Control of temperature
    • G05D23/19—Control of temperature characterised by the use of electric means
    • G05D23/275—Control of temperature characterised by the use of electric means with sensing element expanding, contracting, or fusing in response to changes of temperature
    • G—PHYSICS
    • G05—CONTROLLING; REGULATING
    • G05D—SYSTEMS FOR CONTROLLING OR REGULATING NON-ELECTRIC VARIABLES
    • G05D23/00—Control of temperature
    • G05D23/19—Control of temperature characterised by the use of electric means
    • G05D23/1919—Control of temperature characterised by the use of electric means characterised by the type of controller
    • G05D23/1923—Control of temperature characterised by the use of electric means characterised by the type of controller using thermal energy, the cost of which varies in function of time

Definitions

  • This invention relates generally to peak demand control on utility electrical systems, and more particularly concerns the reduction of a secondary peak of power drawn by a number of distributed electrical loads using energy storage equipment.
  • controller and method will be described in connection with a preferred embodiment utilizing temperature sensitive, electro-mechanical devices employed in novel circuitry, it will be understood that this embodiment does not limit the invention to the electro-mechanical or thermo-mechanical approach.
  • the invention disclosed here also contemplates utilizing electronic storage, and logical circuitry to similarly provide individual and locally adjusted power demands.
  • Use of micro-processors, and non-volatile semiconductor memories, interfaced with the load and utility lines to provide a minimum demand for individual heaters after a power off periods is also contemplated.
  • FIG. (1) Block semi-schematic energy flow diagram showing controller used with stored energy heater in typical heating application.
  • FIG. (2) Typical control panel of the controller showing adjustment dials, and seasonal selector switch.
  • FIG. (3) Circuit diagram of a 3 stage controller.
  • FIG. (4) Time/storage temperatures diagram of a typical application such as shown in FIG. 1 wherein the heated system is a dwelling or similar structure.
  • FIG. (5) Time/storage temp diagram of the system of FIG. 4 at a different ambient temperature.
  • FIG. (6) Time/storage temp diagram of the system of FIG. 4 at another ambient temperature.
  • FIG. (7) is a graphical representation of the power-ambient temperature relationship for the disclosed embodiment of the invention showing functional relationship between storage, and ambient, temperatures, and level of power input to the heater.
  • FIGS. 1, 2, and 3 that is, with a controller operating in the system shown in FIG. 1, wherein the controller 1 is an embodiment having the dial arrangement of FIG. 2 and circuitry according to FIG. 3, and the selector 14 in the winter position.
  • a particularly novel feature of the invention lies in the utilization of three temperature "spans" for the temperature sensitive elements generally indicated as 12 and 13 in FIG. 3.
  • the total temperature range of 12 and 13 is divided into three segments or spans as are the power levels P1, P2, and P3 indicated in FIG. 1. This is accomplished by energizing contactor coils 35, 36, and 37 through thermally actuated contacts 21-27, and associated power contacts 41, 42, and 43, thus energizing heating elements 4 at discrete power levels P1, P2, and P3, from line source 56 or other suitable electrical supply.
  • Sequence controller 40 not a part of this invention provides regulatory time delays in applying power to the heating elements 4.
  • contacts 40a, 40b, and 40c are mechanically actuated by electrical heating of thermal element 40d, after voltage is applied to the primary of transformer 40c.
  • delays in energization and de-energization of the heating elements providing power inputs P1, P2, P3 are achieved.
  • Delay intervals, however, associated with this controller are aimed at minimizing light flicker and line voltage variation, are short in duration and the controller is only included in the disclosure only for the sake of completeness.
  • this span of 35 degrees (i.e. 70.-35.) divided by three establishes approximate temperature set points for switches 27, 26, and 25 of 70° (start of span), 59° (ambient plus two thirds span), and 47° (ambient plus one third span) degrees Fahrenheit respectively.
  • Switches 25, 26, and 27 are actuated sequentially by the thermal element of switch 12 opening at temperatures above their setting, and closed below. Similarly, given a range of storage temperature for 13 of 170 to 290 degrees, three storage limit setpoints of 210, 250, and 290 degrees Fahrenheit are provided.
  • the power levels of 6 kilowatts, 12 kilowatts, and 18 kilowatts, i.e. increments of 6 kilowatts are also exemplary only and represent more or less typical heat losses of the structure having a thermal performance indicated in FIGS. 4, 5, and 6.
  • thermostatic switches operating in preset temperature ranges
  • many other devices could be used to provide similar functions. These would include temperature sensitive resistances, operating in conjunction with electronic apparatus providing electrical signals indicative of the various temperatures.
  • the selector 14 is enabled and as will be described below, depending on the conditions of the controller elements, power draws of 6, 12, and 18 kilowatts are initiated.
  • contactor 35 would be energized via the high contact 32 of 11 since the thermal element of 13 and associated Contacts 31 and 32 are set to close 31 and open 32 above a predetermined minimum storage temperature, i.e., 180° F. and contacts 23 and 27 respectively of switches 13 and 12 now supply six kilowatts of power to storage. This condition is indicated at the location 45 of FIG. 7.
  • Selector 14 provides a circuit change for reduced storage and/or non space heating operation, and are not a part of the disclosed invention. As disclosed, the controller is functioning in the maximum storage or winter position.
  • interlock or "stick” contact 38 a normally open contact actuated by unit 36, as heat is stored and the temperature of storage increases, it will be necessary for that storage temperature to exceed the temperature of contact 22 and 23 of thermostat 13, before the electrical energy controlled by contactor 36 is interrupted. This feature provides a margin of safety and provides essentially increased sensitivity to temperature drop of the storage as opposed to temperature rise.
  • a similar interlock or "stick” contact 39 is provided which requires that storage temperature once having dropped below the setting of contact 21 rise above the contact temperature setting of 23 before power draw is reduced.
  • a controller can, as described above, provide varying power draw as shown in FIG. 7 for various combinations of ambient temperature and residual storage temperature at the initiation of the "power on" period.
  • operation is such as to either eliminate or greatly reduce the initial power draw from a plurality of stored energy heaters at the termination of the power off period. More particularly, in reference to FIG. 4, where heat or storage temperature 46 and total heater power draw is shown at 47 over a 24 hour period, it will be noted that the storage period from 9 PM to 8 AM provides sufficient stored heat to satisfy load requirements over the succeeding power off period from 8 AM to 9 PM.
  • the controls 12 and 13 are set at 35 degrees and 170 degrees Fahrenheit respectively.
  • switches 25, 26, 27, and 21, 22, and 23 provide an ambient span of 35 to 70 degrees Fahrenheit and a storage temperature span of 210 to 290 degrees Fahrenheit respectively.
  • the ambient or outside temperature 5 (ref FIG. 1) is as indicated, 35 degrees.
  • FIG. 5 which is as the above discussed system, a controller, load, and heat input, as shown in FIG. 1, having control settings identical to those of FIG. 4.
  • the load operation is in an ambient or outside temperature of 5 degrees Fahrenheit.
  • the time clock is essentially bypassed, energizing contactor 35 and applying the minimum input to the storage and providing a "base load" 48 of 6 kilowatts during the power off period, the base load temperature is shown on FIG. 5 at point 48.
  • This feature provides heat input to storage and load on the utility which allows a predetermined minimum level of power to be supplied to loads in the event of a sudden or unanticipated demand, such as very low temperatures, high wind losses, and the like. Note that at point 51 as the power on period is initiated, the controller establishes the maximum power draw of 18 kilowatts.
  • point 57 indicates that the storage temperature had reached its maximum prior to the end of the power on period at 8 AM.
  • the actions of the control 13 through its contact 23 provide an upper limit at the preset temperature of 290 degrees as indicated at 48 and 50.
  • the horizontal line between 48 and 50 is only a representative approximation of the actual storage temperature. It is expected that controls cycling around 290 degrees would produce some oscillation of temperature.
  • the horizontal line between 49 and 58 is also a representation and would involve small temperature swings around the minimum temperature of 170 degrees having a frequency and amplitude dependent on the existing load at the time.
  • the system is as shown in FIG. 1, however, the storage temperature setting has been reduced to 216 degrees setting and the ambient temperature is a -5 degrees Fahrenheit.
  • the ambient restriction switch or controller 12 is set at -5°, providing span temperatures of -5° F., +20° F., and +45° F. These adjustments are necessitated by a dual off period requirement, i.e. 8 AM-12 noon, and 4 PM-9:45 PM (ref FIG. 6).
  • points 52, 53, 54, 59, 60, and 61 represent “typical” storage temperatures during “power on” and power off periods for an additionally "typical demand on load extracting heat from storage.
  • a method and controller for minimizing the "secondary peak" demand on a utility system involves utilization of readily available indications of the previous demand on a stored energy heating device through monitoring of its temperature at the onset of a power on period. Further sensitivity to ambient or demand controlling temperatures is provided through continuous measurement of a range of predetermined ambient temperature levels which in conjunction with the monitored residual storage temperature in effect predict the requirements for heat during a succeeding power off period. Additional flexibility is afforded by a provision for adjustment of each range of maximum energy storage temperature and the ambient or load demand temperature providing wide flexibility in the combination of preset temperatures.
  • the method disclosed allows adjustment of individual heaters so that individual load characteristics can be incorporated to control the power draw during the "power on” period, and minimize the secondary peak at the period onset.
  • the novel controller disclosed here in addition to the provision for "tailoring" a stored energy heater to its individual load incorporates a minimum temperature function, which in the event of a demand having low statistical probability of occurrence, will allow the unit to supply its load with a minimum or base load quantity of energy.
  • the controller disclosed above in conjunction with a stored energy heater provides a diversified load which will greatly reduce the level of power drawn at the initiation of a power on period, thereby reducing the above mentioned "secondary peak" substantially.

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  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • Automation & Control Theory (AREA)
  • Control Of Temperature (AREA)
  • Supply And Distribution Of Alternating Current (AREA)
US06/005,304 1979-01-22 1979-01-22 Load controller Expired - Lifetime US4305005A (en)

Priority Applications (5)

Application Number Priority Date Filing Date Title
US06/005,304 US4305005A (en) 1979-01-22 1979-01-22 Load controller
GB7940472A GB2042767A (en) 1979-01-22 1979-11-22 Load controller
CA000340423A CA1144234A (en) 1979-01-22 1979-11-22 Load controller
FR8001232A FR2447125A1 (fr) 1979-01-22 1980-01-21 Procede et dispositif pour commander l'appel de puissance d'appareils de chauffage electrique a accumulation sur un reseau de distribution d'electricite
US06/283,365 US4362949A (en) 1979-01-22 1981-07-15 Load controller having time integrated demand

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US06/005,304 US4305005A (en) 1979-01-22 1979-01-22 Load controller

Related Child Applications (1)

Application Number Title Priority Date Filing Date
US06/283,365 Continuation-In-Part US4362949A (en) 1979-01-22 1981-07-15 Load controller having time integrated demand

Publications (1)

Publication Number Publication Date
US4305005A true US4305005A (en) 1981-12-08

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ID=21715212

Family Applications (1)

Application Number Title Priority Date Filing Date
US06/005,304 Expired - Lifetime US4305005A (en) 1979-01-22 1979-01-22 Load controller

Country Status (4)

Country Link
US (1) US4305005A (ja)
CA (1) CA1144234A (ja)
FR (1) FR2447125A1 (ja)
GB (1) GB2042767A (ja)

Cited By (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4362949A (en) * 1979-01-22 1982-12-07 Vapor Corporation Load controller having time integrated demand
US4449032A (en) * 1983-02-09 1984-05-15 The United States Of America As Represented By The Secretary Of The Air Force Variable gain oven temperature control circuit
US4449178A (en) * 1981-02-27 1984-05-15 Fluidmaster, Inc. Method and apparatus for controlled off peak load hot water heating
US4540875A (en) * 1982-05-04 1985-09-10 Silver Lake Corporation Electric storage heater system having charging control that transmits charging information over power lines
US4874926A (en) * 1988-08-17 1989-10-17 Sanders Steven B Electric heating load management control
US5251320A (en) * 1990-05-25 1993-10-05 International Business Machines Corporation Power controller for permitting multiple processors to power up shared input/output devices and inhibit power down until all processors have ceased service with the I/O devices
US5968393A (en) * 1995-09-12 1999-10-19 Demaline; John Tracey Hot water controller
US6242720B1 (en) * 1998-12-23 2001-06-05 Carrier Corporation Control for electric water heater
EP2224179A3 (de) * 2009-02-26 2013-12-18 Caladia GmbH Heizung für ein Gebäude
US8963353B1 (en) * 2013-09-19 2015-02-24 General Electric Company System and method to minimize grid spinning reserve losses by pre-emptively sequencing power generation equipment to offset wind generation capacity based on geospatial regional wind conditions
US9405304B2 (en) 2013-03-15 2016-08-02 A. O. Smith Corporation Water heater and method of operating a water heater
CN109357310A (zh) * 2018-08-16 2019-02-19 东南大学 热力管网安全与经济运行应急处理系统

Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2156098B (en) * 1984-02-18 1987-07-29 Heat Trace Ltd Control of electric heating apparatus
GB2236406B (en) * 1989-09-12 1993-08-18 Radiant Systems Technology Ltd Radiant heating systems
GB2283809B (en) * 1993-11-12 1997-07-23 Creda Ltd Electrical storage heaters
CN112413702B (zh) * 2020-10-23 2021-11-26 国网天津市电力公司电力科学研究院 一种蓄热式电采暖负荷与配电网台区的匹配方法及系统

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3787729A (en) * 1972-07-13 1974-01-22 Cam Ind Inc Sequencing step control
US4106690A (en) * 1974-11-07 1978-08-15 Rochester Instrument Systems Limited Optimum start controller

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
BE657497A (fr) * 1964-12-23 1965-06-23 Acec Dispositif de commande de la résistance chauffante d'un poêle à accumulation
GB1228722A (ja) * 1967-07-12 1971-04-15
GB1277589A (en) * 1968-12-20 1972-06-14 Simplex Electric Co Ltd Improvements relating to storage heaters
FR2036423A5 (ja) * 1969-03-13 1970-12-24 Ver Volkseigener

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3787729A (en) * 1972-07-13 1974-01-22 Cam Ind Inc Sequencing step control
US4106690A (en) * 1974-11-07 1978-08-15 Rochester Instrument Systems Limited Optimum start controller

Cited By (14)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4362949A (en) * 1979-01-22 1982-12-07 Vapor Corporation Load controller having time integrated demand
US4449178A (en) * 1981-02-27 1984-05-15 Fluidmaster, Inc. Method and apparatus for controlled off peak load hot water heating
US4540875A (en) * 1982-05-04 1985-09-10 Silver Lake Corporation Electric storage heater system having charging control that transmits charging information over power lines
US4449032A (en) * 1983-02-09 1984-05-15 The United States Of America As Represented By The Secretary Of The Air Force Variable gain oven temperature control circuit
US4874926A (en) * 1988-08-17 1989-10-17 Sanders Steven B Electric heating load management control
US5251320A (en) * 1990-05-25 1993-10-05 International Business Machines Corporation Power controller for permitting multiple processors to power up shared input/output devices and inhibit power down until all processors have ceased service with the I/O devices
US5968393A (en) * 1995-09-12 1999-10-19 Demaline; John Tracey Hot water controller
US6242720B1 (en) * 1998-12-23 2001-06-05 Carrier Corporation Control for electric water heater
EP2224179A3 (de) * 2009-02-26 2013-12-18 Caladia GmbH Heizung für ein Gebäude
US9405304B2 (en) 2013-03-15 2016-08-02 A. O. Smith Corporation Water heater and method of operating a water heater
US10753648B2 (en) 2013-03-15 2020-08-25 A. O. Smith Corporation Water heater and method of operating a water heater
US8963353B1 (en) * 2013-09-19 2015-02-24 General Electric Company System and method to minimize grid spinning reserve losses by pre-emptively sequencing power generation equipment to offset wind generation capacity based on geospatial regional wind conditions
US20150076821A1 (en) * 2013-09-19 2015-03-19 General Electric Company System And Method To Minimize Grid Spinning Reserve Losses By Pre-Emptively Sequencing Power Generation Equipment To Offset Wind Generation Capacity Based On Geospatial Regional Wind Conditions
CN109357310A (zh) * 2018-08-16 2019-02-19 东南大学 热力管网安全与经济运行应急处理系统

Also Published As

Publication number Publication date
CA1144234A (en) 1983-04-05
GB2042767A (en) 1980-09-24
FR2447125B1 (ja) 1984-11-16
FR2447125A1 (fr) 1980-08-14

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STCF Information on status: patent grant

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AS Assignment

Owner name: DRC, INC. 803 TAUNTON AVE., EAST PROVIDENCE, RI 0

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNOR:VAPOR CORPORATION A DE CORP;REEL/FRAME:004163/0764

Effective date: 19830613

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Owner name: MEGATHERM, INC., 803 TAUNTON AVE., EAST PROVIDENCE

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNOR:STIEBEL ELTRON NORTH AMERICA, INC., A DE CORP;REEL/FRAME:004231/0147

Effective date: 19830919

Owner name: STIEBEL ELTRON NOTH AMERICA, INC. 84 STATE STREET

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNOR:DRC, INC. A CORP. OF RI;REEL/FRAME:004231/0151

Effective date: 19830610